Some of the recording methods being used as thermal transfer methods include melt transfer recording and sublimal-dye transfer recording, which have been used to realize compact, highly reliable image formation devices.
One example of a regeneration method for the ink sheet is that disclosed in the SID 1985 Digest, pages 143-145. The method disclosed in U.S. Pat. No. 4,467,332 is an ink sheet regeneration method which utilizes a powder ink. As a related technology, an ink sheet regeneration method and device were proposed in Japanese Laid Open Patent Publication 1-295876.
In the method disclosed in the SIP 1985 Digest, pages 143-145, however, a warm-up time is required to melt the ink, much power is required to melt the ink, a mechanism is required to obtain a fixed film thickness for the regeneration ink, the device is large and the mechanism is complicated.
The method disclosed in U.S. Pat. No. 4,467,332 is a regeneration method which uses an ink sheet configured from an ink layer formed on a conductive base film and selectively supplies insulative powder ink to conductive exposed parts after transfer of the ink layer, but since the chargeability of the insulative powder ink varies depending on the environment, the film thickness is not consistent and powder ink adheres to even untransferred parts of the ink layer according to the strength of the electric field. In other words, it is difficult to selectively adhere powder ink to bare areas of the ink layer, and uneven adherence of the powder ink occurs. Therefore, it is difficult to control the ink layer film thickness on the reconditioned ink sheet. This results in an uneven ink layer.
However, the images formed using ink sheet prepared or regenerated by the ink sheet regeneration method and device disclosed in Japanese Laid-Open Patent Publication 1-295876 were high quality images with a high recording density (OD value below), and they also demonstrated a good repetitive characteristic.
The purpose of the present invention is to go beyond that disclosed in Japanese Laid-Open Patent Publication 1-295876 by offering an image formation device which more effectively utilizes the ink sheet and greatly reduces operating costs. Another purpose of the invention is to offer an image formation device with a mechanism for ink sheet regeneration capable of easily accommodating color printing.